1. Field of the Invention
This application concerns a vehicle fuel filling system of the type using a fuel vapor retaining canister to store fuel vapors displaced from a fuel tank as the tank is refilled with liquid fuel and more specifically a dry air purge system for the canister.
2. Description of Related Art
Apparatus and systems for vehicles to prevent the discharge of fuel vapors to atmosphere are known. Apparatus of this type normally uses a fuel vapor storage canister filled with activated charcoal or the like to temporarily store fuel vapors. The escape of fuel vapors which are displaced from the fuel tank during a filling operation should be avoided. After being collected in the charcoal canister, these vapors must then be purged from the activated charcoal while the vehicle engine is running. This is accomplished by drawing air through the canister and into the engine's intake manifold.
An earlier filled patent application by co-workers of the present inventor concerns a filler device for a tank to prevent escape of fuel vapors to atmosphere. This application is Ser. No. 07/378,567 by M. Teets et al. entitled "Fuel Filler Assembly," filed July 11, 1989, now U.S. Pat. No. 4,966,299. It does not disclose air inletting for a purge system for a canister.
U.S. Pat. No. 4,770,677 to Harris discloses a filler device for a fuel tank to prevent escape of vapor and also shows a canister purge system. Harris does not disclose a dry air inletting system for purging a canister as in the subject application.